Disposable pipette tips are often packaged within trays that function to support and organize the pipette tips and to aid in the placement of one or more pipette tips onto a pipetter having one or more channels. These trays may be housed within a container or rack that is convenient for bench-top applications.
Often, the trays are either refillable, i.e., pipette tips may be reloaded into an empty tray, which may or may not be sterilized between uses, or disposable and replaceable with a filled tray. In either situation, multiple trays may be packaged together in a stack for storage convenience and for efficient reloading of a rack with a new filled tray of pipette tips after the previous tray is emptied of its pipette tips during use. However, the stacking of multiple trays containing pipette tips is not straightforward because the overall length of each pipette tip is often greater than the thickness of the tray. That is, the shafts of the pipette tips extend beyond the bottom of each tray. Simply stacking the trays would cause the distal tip ends of the pipette tips in an upper tray to fall within the lumens of the pipette tips in a lower tray. When an upper tray is then removed from the stack, the pipette tips of the lower tray may be ejected from the lower tray along with the upper tray. This defeats the organizational purposes and convenience of stackable trays.
While in some applications this may not present a problem, the known conventional stacking arrangements are not practical for stacking trays containing filter pipette tips. Filter pipette tips have a structure that is similar to standard pipette tips but further include a semi-porous structure within the lumen of the pipette tip. As a result, the distal tip ends of the filter pipette tips in an upper tray cannot fall within the lumens of the filter pipette tips in a lower tray without interfering and/or damaging the semi-porous structure and/or the pipette tip. Because known alternative arrangements for stacking pipette tip trays have not provided satisfactory solutions for filter pipette tips, i.e., stacking is neither efficient with respect to storage capability nor conducive to the laboratory environment where technicians often wear gloves with diminished dexterity or handling by laboratory robotics, there remains a need for a pipette tip tray that is capable of supporting pipette tips, particularly filter pipette tips, and that is stackable in a simple but efficient manner for use with a pipette tip rack.